New CLAUDE_CODE_AUTOUPDATER_DISABLED_BY_HOST lets a host stop plugin auto-updates

What

Claude Code now reads a new environment variable, CLAUDE_CODE_AUTOUPDATER_DISABLED_BY_HOST. An environment variable is a setting passed to a program from outside, here by a host program that starts Claude Code. Plugins are add-ons that extend Claude Code.

• Plugin auto-update is now switched off when the existing updater-disabled check fires or when the host's version pin applies. Otherwise the old behaviour is unchanged.
• FORCE_AUTOUPDATE_PLUGINS still overrides this and forces plugin updates.
• When the host pin turns plugin auto-update off, the debug log shows a message starting Plugin autoupdate: off under the host's pin.
• The variable is added to the lists of environment keys passed on when a host starts Claude Code.
• The updater-disabled check now receives the DISABLE_AUTOUPDATER state as an input instead of reading it directly.

The startup environment check also reads another new variable, CLAUDE_CODE_SLEEP_COMPACT, and gains a new case-insensitive check for CLAUDE_CODE_REMOTE_TOOLS_FORWARD. The members do not say what these two do.

Why

If you use Claude Code inside another program that pins its version, your plugins can now stay at fixed versions alongside it instead of updating on their own. If you need plugin updates anyway, FORCE_AUTOUPDATE_PLUGINS still wins.